The present invention relates generally to medical devices and, more particularly, to devices and methods for attenuating the formation of post-surgical adhesions between a post-surgical site and adjacent surrounding tissue.
A major clinical problem relating to surgical repair or inflammatory disease is adhesion which can occur during the initial phases of the healing process after surgery or disease. Adhesion is a condition which involves the formation of abnormal tissue linkages. These linkages can for example impair bodily function, produce infertility, obstruct the intestines and other portions of the gastrointestinal tract (bowel obstruction) and produce general discomfort, e.g. pelvic pain. The condition can in some instances be life threatening. The most common form of adhesion occurs after surgery as a result of surgical interventions, although adhesion may occur as a result of other processes or events such as pelvic inflammatory disease, mechanical injury, radiation treatment and the presence of foreign material.
Various attempts have been made to prevent postoperative adhesions. For example, the use of peritoneal lavage, heparinized solutions, procoagulants, modification of surgical techniques such as the use of microscopic or laparoscopic surgical techniques, the elimination of talc from surgical gloves, the use of smaller sutures and the use of physical barriers (membranes, gels or solutions) aiming to minimize apposition of serosal surfaces, have all been attempted. Unfortunately, limited success has been seen with these methods. Barrier materials, in various forms such as membranes and viscous intraperitoneal solutions, which are designed to limit tissue apposition, have also met with only limited success. A few of these barrier materials include cellulosic barriers, polytetrafluoroethylene materials, and dextran solutions.
U.S. Pat. No. 5,795,584 to Tokahura et al. discloses anti-adhesion or scar tissue reduction films or membranes, and U.S. Pat. No. 6,136,333 to Cohn et al. discloses similar structures. In the Tokahura et al. patent, a bioabsorbable polymer is copolymerized with a suitable carbonate and then formed into a non-porous single layer adhesion barrier, such as a film. In the Cohn et al. patent a polymeric hydrogel for anti-adhesion is formed without crosslinking by using urethane chemistry. Both of these patents involve relatively complex chemical formulas and/or reactions to result in particular structures to be used as surgical adhesion barriers.
Resorbable polylactide polymer scar tissue reduction barrier membranes and methods of their application have been discovered. In accordance with one aspect of the present invention, the scar-tissue reduction barrier membranes are constructed entirely of polylactide resorbable polymers, which are engineered to be absorbed into the body relatively slowly over time in order to reduce potential negative side effects. The scar tissue reduction barrier membranes are formed to have thicknesses on the order of microns, such as, for example, thicknesses between 10 and 300 microns. The membranes are preshaped with welding flanges and stored in sterile packaging.